The present invention relates to magazines including an endless length of strip material, machines including a transducer for recording and/or reading signals on the strip material in the cartridge, and the method used by the combination for moving the strip material past the transducer; and in one important aspect to such a magazine containing magnetic tape and used in a magnetic recording and/or playback machine.
Magazines are known which include an endless loop of strip material or tape and means for supporting the tape for travel along a path past access areas defined in the magazine at which the tape may be engaged by means in a machine to drive it along the path past a transducer for recording and/or reading signals.
Such a magazine for an endless length of magnetic recording tape is described in U.S. Pat. No. 3,350,025. Magazines or cartridges generally of the type described in that patent include a hub about which the tape is wrapped to form a coil, and guides for guiding the tape from the innermost wrap of the coil, around one edge surface of the coil, past tape access areas defined on the cartridge, and then to the outermost wrap of the coil. A drive mechanism in a recording and/or playback machine can engage the tape at the tape access areas to pull it from the innermost wrap of the coil past transducers or record and playback heads in the machine. The guides in this type of cartridge provide most of the guiding for movement of the tape past the heads on the machine in which the cartridge is mounted, however. Thus the tape will be driven along a slightly inaccurate path past the head resulting in a significant phase error in the signal produced by the machine if only slight misalignment occurs between the transducers in the machine and guides for the tape in the cartridge mounted in the machine. Such misalignment can occur by inadvertently tilting the cartridge slightly when it is engaged with the machine, or will even occur because of dimensional variations in the housing portions of various cartridges which affect the position at which those cartridges are engaged by the machine.
Thus, while cartridges generally of this type have found some use in broadcast studios for prerecorded voice messages (such as commercials) where such signal errors are not easily detectable, they have not been widely used for reproducing music. Instead, broadcast studios have continued to use reel to reel recorders, which, despite their relative inconvenience, are far less subject to such signal errors.
Also, in a cartridge of the type described in U.S. Pat. No. 3,350,025 the tape is twisted and guided around the side surface of the coil while it is under tension from the tape drive means in a machine in which the magazine is mounted. This tends to wear the tape at a rapid rate, thereby reducing the useful life of the tape in the cartridge.